When he's in the guest seat, Howard Stern has a tendency to get a bit solipsistic. He's also an indefatigable gossip who loves to trash other media personalities. To wit, Tuesday night on "The Daily Show," Stern sat down for a chat with Jon Stewart and was clearly eager to talk shop.

As one does in polite conversation, Stern opened the segment by asking Stewart how much he makes. He also brought up something he'd read in Bill Carter's book, "The War for Late Night" (he mentioned the book on "The Late Show" earlier this month) about NBC trying to woo Jon Stewart to replace Conan O'Brien. It was a touch awkward to see Jon Stewart deny the rumors, though he did so gracefully.

The conversation, naturally, turned to the subject of Charlie Sheen. Stern told Stewart that he had tracked down Sheen's cellphone number and that star had tentatively agreed to appear on his show on Wednesday. Stewart seemed genuinely bemused by Sheen's "lunatic" antics, which provoked Stern to ask a question: "Who is more insane, Charlie Sheen or Glenn Beck?

Stewart didn't hesitate to answer. "I'm gonna go with the guy whose skin you can flake off and smoke like crack." In case it's unclear, he meant Charlie Sheen. Stewart seemed to think that the tough-talking Stern might be the only talk-show host who could really talk some sense into the former "Two and a Half Men" star.

Stern agreed. "Like Chinese water torture, we wear you down until we get the truth."